在淮南矿区复杂地质条件低透气性煤层群卸压开采抽采瓦斯多年创新和实践的基础上，提出了首采卸压层无煤柱沿空留巷Y型通风煤气共采新思路；通过对采空区边缘岩体结构变形破坏和裂隙演化规律的分析，揭示了采动影响区内顶底板岩层裂隙的动态演化规律、Y型通风方式下采空区的空气压力场分布及卸压瓦斯的流动规律，通过分析沿空留巷围岩大小结构的变化规律，提出了基于锚杆支护的“三位一体”留巷围岩控制技术；研发成功新型CHCT充填材料、强支撑自移模板液压充填支架、干混料集装箱以及充填泵上料系统，建立机械化快速构筑充填墙体工艺系统，发展和创新了低透气性煤层群无煤柱煤气共采的理论及关键技术。

This thesis, based on innovations and practices of methane drainage in multiseams of low permeability and complicated geology in Huainan mining district, systematically describes theories and key technologies of integrated pillarless coal production and methane extraction with "Y"  type ventilation system in multiseams of low permeability. Through analyses of deformation, fracturing and failure of rocks around goaf, methane movement and accumulation in and around the goaf are revealed, technologies to retain goaf edge roadways with innovative fill technologies are developed, and technological innovations in methane extraction are made with the retained goaf edge roadways and "Y"  type ventilation systems.